Tennis String Guide


Although strings are made from a wide variety of materials, the three most common are nylon, polyester and the serous membrane of cow intestines. These materials are deployed across four construction types: synthetic gut (nylon solid core with one or more wraps), multifilament (1,000+ nylon microfibers), polyester/co-polyester (polyester-based monofilament) and natural gut (strands from serous membranes). Each type of string generally has the following characteristics: 

  • Natural Gut - the original and most playable, but not the most durable.
  • Synthetic Gut / Nylon - for good all round performance.
  • Multifilament strings - for gut like characteristics.
  • Polyesters  - The most popular and best for string breakers. The latest "softer" Polyesters and Multifilament Polyesters - the latest innovation, are less harsh on the arm.

There is always a compromise between playability and durability, with natural gut and multifilament strings being the most playable and poly strings being the most durable. This has led to the current fashion for combining different strings on the mains (vertical) and crosses (horizontal). The classic example of this is Roger Federer, whose Champions Choice strings consist of a strong poly and natural gut. Rafa Nadal uses a soft poly string all round (Babolat RPM Blast).

Natural Gut - Maximum Comfort | Power | Feel | Tension Maintenance

Generally, a playable string snaps back quickly upon ball impact. The material, construction, and thickness of a string will all affect the playability of a string. The best string for playability at this time is still natural gut.

Made from the fibrous and stretchy serous membrane of cow intestines, natural gut is the game’s most storied and iconic string type. Although it has been around since the 1800s, the tennis industry has yet to create an alternative that captures the magic of its elasticity, including the unrivalled comfort, power and feel that flows from it. Natural gut also retains its tension and optimal playing characteristics longer than any other string type, a fact reflected in its premium price tag. In addition to being a popular pick for players with tennis elbow or sensitive joints, natural gut is singular in that it can be tightly tensioned for control and spin without compromising comfort.


  • Optimum playability
  • Best tension maintenance
  • Good arm comfort
  • Remains playable at very high tensions


  • Most expensive string type
  • Less durable than other string types

Multifilaments - Comfort | Power | Feel

Although it is impossible to replicate the feel and power of natural gut, multifilament strings are a more affordable alternative for many players. In order to mimic the stranded and flexible construction of natural gut, multifilament's use ultra pliable synthetic fibres to help absorb impact shock and load the ball with power. In addition to being friendly to your joints and tendons, this string type will help you keep the ball deep and frustrate your opponent with higher levels of pace. Not recommended to string breakers.

Some of the latest multifilament strings are a more than adequate substitute for natural gut given that they are more durable with good playability and more reasonably priced.

Some of the most popular playability strings include: Babolat X-Cel, Tecnifibre NRG2, Tecnifibre X-One BiPhase and Wilson Sensation or NXT. 


  • Very good playability
  • Wide range of price points
  • Softer on the arm
  • Very good tension maintenance
  • Closest thing to natural gut


  • Less control oriented
  • Certain multifilament can feel "mushy"
  • Less durability for bigger hitters

Polyester - Maximum Control | Spin | Durability

Polyester strings are for experienced players who require maximum control, spin and durability. Polyester’s playability lies in its stiff monofilament construction, which gives strong players the needed control to swing bigger without fear of overhitting. The upshot is more confidence when playing aggressive tennis. Although generally too firm and underpowered for beginners, polyester string construction has benefited from the increasing use of softening agents, resulting in a more user-friendly hitting experience for newcomers. Don’t be confused by the term co-polyester (co-poly), which is used to denote the use of chemical additives.


  • Durable
  • Lots of control
  • Lots of spin


  • Low powered
  • Harsher on the arm
  • Loses tension faster

Synthetic Gut - All-around playability | Value | Ideal for beginners

If you’re not sure which string you need, start with synthetic gut. Made of nylon, synthetic gut is a basic solid core string that is enclosed by one or more wraps to enhance performance. Synthetic gut combines an easy learning curve with a value for money price. Although this string isn’t recommended to advanced players and string breakers.


  • Economically priced
  • Good all-around choice
  • Average overall performance & playability
  • Not extraordinary in any category


Gauges are essentially the thickness of a string. The higher the gauge, the thinner the string. The problem with gauges however, is that there is not a standardised and universal chart. A 16 gauge for one brand might be a 16L (L stands for "light," which basically means it's halfway between two gauges, think of a 16L as a 16.5) for another. This is why we recommend referencing the actual millimetre sizing which is shown generally next to the gauge on string packaging. In general, thinner string will provide more power and spin by allowing the strings to embed into the ball more, while thicker strings provide more control and durability. 

Thinner strings are less durable, but you could allow for that by going for a really thin, durable string. Thicker gauges will be more durable, but they are less elastic and resilient than their thinner counterparts. 

Tennis string gauges range from 15 (thickest) to 20 (thinnest):

  • Gauge 15 (1.35 mm) is the standard gauge for tennis.
  • Gauge 16 (1.30 mm) is the most popular gauge for tennis (optimum level of durability and power)
  • Gauge 17 (1.25 mm) is "thinner than normal" gauge for tennis. 
  • Gauges above 17 are classed as very thin string. 

Unfortunately, increased durability in tennis strings is usually at the expense of playability. As general advise we would suggest if a player is breaking a 16 gauge string, we might recommend they switch to a 15 gauge version of that same string, if available, for more durability.


Each racket has its own tension range (shown in the technical spec of each racket).

The optimum tension for the majority of people is mid-tension. We would recommend picking a tension 1 or 2 lbs more than mid as rackets lose tension fairly quickly.

Typically, players who generate their own power will string with a higher tension and vice versa for a beginner. If you don't know what tension to string with, we recommend you choose the the middle tension and then you can make adjustments from there on. Need more power? Go down 2-3 pounds next time you restring your racket. 

Generally speaking, the higher the tension, you get more control (less power). The lower the tension, you get more power (less control). The higher the tension also means more impact on your arm.

If you go for a durable poly string for both mains and crosses, you should reduce the tension by up to 10% as poly strings have no give in them, and can cause arm issues.

For the majority of people, the same mains and crosses are ideal, but you can ask for custom mains and crosses ie a Hybrid selection or you can pick from a selection of Pre-selected Hybrid sets.

Not all strings and tensions are correct for every player. Each player has different needs and preferences. 

You can request your racket to be strung above the maximum recommended tension of the frame but that will void the warranty for the racket.


Contrary to popular belief, breaking a string isn't the only time you should restring your racket. For the casual recreational player, a good rule of thumb to follow is to restring as many times in a year as you play in a week. For example, if you play 5 times a week, then you should restring at least 5 times a year. But if you use polyester string, we would recommend stringing more often. When a string has lost most of its tension it loses most of its playability, which includes power, control and feel.